Tractor backhoe - homemade

[BFreaky]

2nd boom assembly

 

[Kyle_in_Tex]

I hope your leg is better.

Good work. Still watching.

 

[4570Man]

Did you end up using the Hardox or is it regular mild steel?

 

[BFreaky]

Wear parts are gonna be Hardox, the rest is S355MC. It will be fine, no worries

 

[Renze]

is it fairly easy to push that sheet of steel around the curve, or did you have to put a pipe wrench on the handle of your clamps ?

And what was the wall thickness of top and bottom plates, 8 or 10mm ?

 

[BFreaky]

It's a small curve but it was quite hard to bend. I have to make a hydraulic shop press...it would come in handy many times. Its 8mm plate, 180 mm width, approx 2 m lenght. Why do you ask? Rk 525 had 10 mm but I think it was too much...

 

[Renze]

Its 8mm plate, 180 mm width, approx 2 m lenght. Why do you ask? Rk 525 had 10 mm but I think it was too much...

I ask because at work, we never work with steel thinner than 15mm in booms. That is, for machines from 30 to 250 ton operating weight

But i am thinking of building my own backhoe as well, the Bobcat attachment i modified for tractor use, is too limited for any foundation digging.

 

[BFreaky]

Well, now I'm sure this is too thick.... What size of bh do you plan to build?

 

[4570Man]

8mm is more than 1/4 thick. I don’t think the boom on my 310 is any heavier. Making a boom ridiculous overkill has no benefits and plenty of negatives. Upwards of 15mm on the boom would result in something his tractor couldn’t even move.

 

[aczlan]

8mm is more than 1/4 thick. I don’t think the boom on my 310 is any heavier. Making a boom ridiculous overkill has no benefits and plenty of negatives. Upwards of 15mm on the boom would result in something his tractor couldn’t even move.

8mm is ~5/16" that's pretty thick.

Aaron Z

 

[BFreaky]

If you compare this one with rk 525, it had 10 mm top and bottom plates, 8 mm side plates and larger profile height. I managed to reduce the weight of the machine by 400 kg by now. When it's finished I plan to take it to drive on scale to measure the weight of complete machine

 

[dfkrug]

It's a small curve but it was quite hard to bend.

8mm is pretty thick, as noted by others. You should use some heat with an O/A torch while bending. It does not need to get very hot. I once built a 13" wide bucket for my home-built CADDigger, and it called for 1/4" plate, bent around some side plates. I was surprised that I was able to bend it at all with 2 cheapo come-alongs and a torch.

Now I know better. 3/16" plate would have been fine, with wear plates where needed. With all those fine gussets you made, BF, you can go thinner on the carcass. Sometimes even 1/8" is enough, esp with exotic steels, wear plates, and gussets.

Looks great.

 

[Renze]

8mm is more than 1/4 thick. I don稚 think the boom on my 310 is any heavier. Making a boom ridiculous overkill has no benefits and plenty of negatives. Upwards of 15mm on the boom would result in something his tractor couldn稚 even move.

I didnt propose 15mm for his backhoe, i was just wondering how easy it is to bend 8mm into the shape of the boom, because at work, we work with substantially heavier material which is bent with a press. For what im thinking of building, i'm unsure if i want 6 or 8mm, i could build it lighter with 6mm and a higher cross section, but have more risk of getting local cracks where cylinder brackets are welded to the top and bottom plates of the boom.

With 6mm i wouldnt need brake pressing a dozen steps to create a radius like we do at work, but what i understand from Bfreaky, 8mm is too strong to clamp into a curve..

 

[Renze]

...just to clarify once more: at work we build booms for 30 to 250 ton exvavators, but i am thinking of building a backhoe for myself, which would compare to a 3 ton excavator. Which is a machine size of which Bfreaky has more experience with, than me

 

[Oldpath05]

What page or year is the finished BH on?

 

[ptsg]

What page or year is the finished BH on?

Page 20/21 I believe.

That was the first one that BFreaky built. He is now on a second one that will be improved.

 

[BFreaky]

Renze, it's not too hard to bend, you just have to use 2 really large clamps with trapezoid thread and press the plate every 20 cm step by step and it works. If that fails you can always use small hydraulic jack with O frame. That was my plan B in case clamps couldn't do it.

 

[BFreaky]

Thick parts for kingpost and boom no.3.

 

[Rustyiron]

CAD, wow! Sure wish I could grasp this dam* computer "thing":laughing:
As usual, amazing BF:thumbsup:

 

[JKR]

Fanstaic work. Was the peices cut with a water Jet?